[PARISC] import necessary bits of libgcc.a

Currently we're hacking libs-y to include libgcc.a, but this has
unforeseen consequences since the userspace libgcc is linked with fpregs
enabled. We need the kernel to stop using fpregs in an uncontrolled manner
to implement lazy fpu state saves.

Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>

1 files changed, 46 insertions, 0 deletions

diff --git a/arch/parisc/lib/libgcc/__umulsidi3.c b/arch/parisc/lib/libgcc/__umulsidi3.c
new file mode 100644
index 00000000000..396f669164d
--- /dev/null
+++ b/arch/parisc/lib/libgcc/__umulsidi3.c
@@ -0,0 +1,46 @@
+#include "libgcc.h"
+
+#define __ll_B ((u32) 1 << (32 / 2))
+#define __ll_lowpart(t) ((u32) (t) & (__ll_B - 1))
+#define __ll_highpart(t) ((u32) (t) >> 16)
+
+#define umul_ppmm(w1, w0, u, v)						\
+  do {									\
+    u32 __x0, __x1, __x2, __x3;						\
+    u16 __ul, __vl, __uh, __vh;						\
+									\
+    __ul = __ll_lowpart (u);						\
+    __uh = __ll_highpart (u);						\
+    __vl = __ll_lowpart (v);						\
+    __vh = __ll_highpart (v);						\
+									\
+    __x0 = (u32) __ul * __vl;						\
+    __x1 = (u32) __ul * __vh;						\
+    __x2 = (u32) __uh * __vl;						\
+    __x3 = (u32) __uh * __vh;						\
+									\
+    __x1 += __ll_highpart (__x0);/* this can't give carry */		\
+    __x1 += __x2;		 /* but this indeed can */		\
+    if (__x1 < __x2)		 /* did we get it? */			\
+      __x3 += __ll_B;		 /* yes, add it in the proper pos.  */	\
+									\
+    (w1) = __x3 + __ll_highpart (__x1);					\
+    (w0) = __ll_lowpart (__x1) * __ll_B + __ll_lowpart (__x0);		\
+  } while (0)
+
+union DWunion {
+	struct {
+		s32 high;
+		s32 low;
+	} s;
+	s64 ll;
+};
+
+u64 __umulsidi3(u32 u, u32 v)
+{
+	union DWunion __w;
+
+	umul_ppmm(__w.s.high, __w.s.low, u, v);
+
+	return __w.ll;
+}